Rationalise ThreadPoolTaskExecutor and ScheduledExecutorFactoryBean [SPR-5337]

[spring-projects-issues]

Kenny MacLeod opened SPR-5337 and commented

There is currently a gap in functionality between ThreadPoolTaskExecutor, which is offers lots of ways of configuring a ThreadPoolExecutor but hides it behind a TaskExecutor facade, and SheduledExecutorFactoryBean, which generates a ScheduledThreadPoolExecutor and is a FactoryBean.

It feels like these two should be brought together somehow. I've created a subclass ThreadPoolTaskExecutor which implements FactoryBean and exposes the native ThreadPoolExecutor. I think that SheduledExecutorFactoryBean could itself just be a subclass of ThreadPoolTaskExecutor, but which overrides the method which creates the executor instance.

So, how about a class called ThreadPoolExecutorFactory, which provides facilities for configuring and instantiating ThreadPoolExecutor instances, and then a variety of subclasses of this, including ThreadPoolTaskExecutor (which wraps the ThreadPoolExecutor in a TaskExecutor facade), and ThreadPoolExecutorFactoryBean (which exposes the ThreadPoolExecutor directly). SheduledExecutorFactoryBean would simply become a special case of ThreadPoolExecutorFactoryBean.

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Affects: 2.5.6

[spring-projects-issues]

Juergen Hoeller commented

I've added a ThreadPoolExecutorFactoryBean (exposing the native ExecutorService API) analogous to ScheduledExecutorFactoryBean (exposing the native ScheduledExecutorService API). Both share a common base class with configuration properties now.

ThreadPoolTaskExecutor continues to exist as a JMX-capable Spring TaskExecutor implementation, using a ThreadPoolExecutor underneath but with different design tradeoffs in terms of being a Spring component.

Note that Spring 3.0 has plenty of further concurrency enhancements: TaskExecutor extends Executor now; AsyncTaskExecutor has "Future submit(Runnable)" and "Future submit(Callable)" methods; we ship an ExecutorServiceAdapter class as a standard wrapper for a Spring TaskExecutor; etc.

Juergen